检索结果-南通市图书馆

One-step estimation for varying coefficient models

在线全文

学校读者我要写书评

暂无评论

science china Mathematics 2005年第2期48卷 198-213页

作者： TANG Qingguo & WANG Jinde department of Mathematics, nanjing university, nanjing 210093, china Institute of sciences, PLA university of science and technology, nanjing 210007, china 1. department of Mathematics Nanjing University 210093 Nanjing China 2. Institute of sciences PLA University of Science and Technology 210007 Nanjing China

A one-step method is proposed to estimate the unknown functions in the varying coefficient models, in which the unknown functions admit different degrees of smoothness. In this method polynomials of different orders are used to approximate unknown functions with different degrees of smoothness. As only one minimization operation is employed, the required computation burden is much less than that required by the existing two-step estimation method. It is shown that the one-step estimators also achieve the optimal convergence rate. Moreover this property is obtained under conditions milder than that imposed in the two-step estimation method. More importantly, as only one minimization operation is employed, the full asymptotic properties, not only the asymptotic bias and variance, but also the asymptotic distributions of the estimators can be derived. The asymptotic distribution results will play a key role for making statistical inference.

关键词： varying coefficient model, one-step estimation, asymptotic distribution, optimal convergence rate.

Wavelet estimation of the diffusion coefficient in time dependent diffusion models

在线全文

学校读者我要写书评

暂无评论

science china Mathematics 2007年第11期50卷 1597-1610页

作者： Ping CHEN~(1,2+) Jin-de WANG~1 1 department of Mathematics,nanjing university,nanjing 210093,china 2 School of science,nanjing university of science and technology,nanjing 210094,china department of Mathematics Nanjing University Nanjing 210093 China School of science Nanjing University of Science technology Nanjing 210094 China

The estimation problem for diffusion coefficients in diffusion processes has been studied in many papers,where the diffusion coefficient function is assumed to be a 1-dimensional bounded Lipschitzian function of the state or the time *** is no previous work for the nonparametric estimation of time-dependent diffusion models where the diffusion coefficient depends on both the state and the *** paper introduces and studies a wavelet estimation of the time-dependent diffusion coefficient under a more general assumption that the diffusion coefficient is a linear growth Lipschitz *** the properties of martingale,we translate the problems in diffusion into the nonparametric regression setting and give the Lr convergence rate.A strong consistency of the estimate is *** this result one can estimate the time-dependent diffusion coefficient using the same structure of the wavelet estimators under any equivalent probability *** example,in finance,the wavelet estimator is strongly consistent under the market probability measure as well as the risk neutral probability measure.

关键词： wavelet estimation time-dependent diffusion coefficient linear growth condition strong consistency

Reducing component estimation for varying coefficient models with longitudinal data

在线全文

学校读者我要写书评

暂无评论

science china Mathematics 2008年第2期51卷 250-272页

作者： TANG QingGuo~(1,2+) WANG JinDe~2 1 Institute of sciences,People’s Liberation Army university of science and technology,nanjing 210007,china 2.department of Mathematics,nanjing university,nanjing 210093,china 1. Institute of sciences People’s Liberation Army University of Science and Technology Nanjing 210007 China 2. department of Mathematics Nanjing University Nanjing 210093 China

Varying-coefficient models with longitudinal observations are very useful in epidemiology and some other practical *** this paper,a reducing component procedure is proposed for es- timating the unknown functions and their derivatives in very general models,in which the unknown coefficient functions admit different or the same degrees of smoothness and the covariates can be time- *** asymptotic properties of the estimators,such as consistency,rate of convergence and asymptotic distribution,are *** asymptotic results show that the asymptotic variance of the reducing component estimators is smaller than that of the existing estimators when the coefficient functions admit different degrees of *** sample properties of our procedures are studied through Monte Carlo simulations.

关键词： varying coefficient model longitudinal data nonparametric estimation reducing component estimators asymptotic normality 62G07

Web Application Comprehension Based on Dependence Analysis

在线全文

学校读者我要写书评

暂无评论

Wuhan university Journal of Natural sciences 2004年第5期9卷 731-734页

作者： WU Jun-hua 1,2 , XU Bao-wen 1 , JIANG Ji-xiang 1 1.department of computer science and Engineering, Southeast university, nanjing 210096, jiangsu, china 2.College of computer science and Engineering, nanjing university of technology, nanjing 210009, jiangsu , china Southeast university Department of Computer Science and Engineering Nanjing Jiangsu China (GRID:grid.263826.b) (ISNI:***) Najing university of technology College of Computer Science and Engineering Nanjing Jiangsu China (GRID:grid.41156.37) (ISNI:***) Southeast university Department of Computer Science and Engineering Nanjing Jiangsu China (GRID:grid.263826.b) (ISNI:***)

Many research indicate a lot of money and time are spent on maintaining and modifying program delivered. So the policies to support program comprehension are very important. Program comprehension is a crucial and difficult task. Insufficient design, illogical code structure, short documents will enhance the comprehensive difficulty. Developing Web application is usually a process with quick implementation and delivery. In addition, generally a Web application is coded by combining mark language statements with some embedded applets. Such programming mode affects comprehension of Web applications disadvantageously. This paper proposes a method to improving understanding Web by dependence analysis and slice technology. Key words Web application comprehension - program dependence - hyper graph - pogram slicing CLC number TP 311 Foundation item: Supported in part by the Young Scientist’s Fund of NSFC (60373066, 60303024). National Grand Fundamental Research 973 Program of china (2002CB312000) and National Research Foundation for the Doctoral Program of Higher Education of chinaBiography: WU Jun-hua (1965-), female, Ph. D. research direction: software engineering.

关键词： Web application comprehension program dependence hyper graph pogram slicing

Technical framework for Internetware: An architecture centric approach

在线全文

学校读者我要写书评

暂无评论

science in china(Series F) 2008年第6期51卷 610-622页

作者： YANG FuQing1,2, Lü Jian3,4 & MEI Hong1,2 1 Key Laboratory of High Confidence Software Technologies (Peking university), Ministry of Education, Beijing 100871, china 2 School of Electronics Engineering and computer science, Peking university, Beijing 100871, china 3 State Key Laboratory for Novel Software technology, nanjing 210093, china 4 department of computer science and technology, nanjing university, nanjing 210093, china 1. Key Laboratory of High Confidence Software Technologies (Peking university) Ministry of Education Beijing 100871 China 2. School of Electronics Engineering and computer science Peking University Beijing 100871 China 3. State Key Laboratory for Novel Software technology Nanjing 210093 China 4. department of computer science and technology Nanjing University Nanjing 210093 China

Being a new software paradigm evolved by the Internet, Internetware brings many challenges to the traditional software methods and techniques. Sponsored by the national basic research program （973）, researchers in china have developed an architecture centric technical framework for the definition, incarnation and engineering of Internetware. First of all, a software model for Internetware is defined for what to be, including that Internetware entities should be packaged as components, behaving as agents, interoperating as services, collaborating in a structured and on demand manner, etc. Secondly, a middleware for Internetware is designed and implemented for how to be, including that Internetware entities are incarnated by runtime containers, structured collaborations are enabled by runtime software architecture, Internetware can be managed in a reflective and autonomic manner, etc. Thirdly, an engineering methodology for Internetware is proposed for how to do, including the way to develop Internetware entities and their collaborations by transforming and refining a set of software architectures which cover all the phases of software lifecycle, the way to identify and organize the disordered software assets by domain modeling, etc.

关键词： Internetware component software architecture agent middleware

Variational construction of unbounded orbits in Lagrangian systems

在线全文

学校读者我要写书评

暂无评论

science china Mathematics 2010年第3期53卷 617-624页

作者： CHENG Chong-Qing 1, & LI Xia 2 1 department of Mathematics, nanjing university, nanjing 210093, china 2.department of Mathematics, Suzhou university of science and technology, Suzhou 215001, china 1. department of Mathematics Nanjing University Nanjing 210093 China2. Department of Mathematics Suzhou University of Science and Technology Suzhou 215001 China

We show the existence of unbounded orbits in perturbations of generic geodesic flow in T2 by a generic periodic potential. Different from previous work such as in Mather (1997), the initial values of the orbits obtain... 详细信息

关键词： positive definite Lagrangian variational method unbounded orbit

Loop reduction techniques for reachability analysis of linear hybrid automata

在线全文

学校读者我要写书评

暂无评论

science china(Information sciences) 2012年第12期55卷 2663-2674页

作者： PAN MinXue,LI You,BU Lei & LI XuanDong State Key Laboratory for Novel Software technology,department of computer science and technology,nanjing university,nanjing 210093,china 1. State Key Laboratory for Novel Software technology Department of Computer Science and Technology Nanjing University Nanjing 210093 China

The problem of reachability analysis of linear hybrid automata(LHA) is very *** paper considers to improve the efficiency of the reachability analysis by optimizing the structures of *** identify two types of loops called the flexible loops and the zero loops,and present the techniques to replace the repetitions of those loops in the behavior of LHA with finite sequences of locations and in the meantime simplify the associated *** techniques work not only for the polyhedral computing based algorithms but also for the bounded model checkers.

关键词： real-time and hybrid systems linear hybrid automata reachability analysis

Dynamic damage and stress-strain relations of ultra-high performance cementitious composites subjected to repeated impact

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science china(Technological sciences) 2010年第6期53卷 1520-1525页

作者： LAI JianZhong1 & SUN Wei2 1 department of Materials science and Engineering,nanjing university of science and technology,nanjing 210094,china 2 College of Materials science and Engineering,Southeast university,nanjing 211189,china 1. department of Materials science and Engineering Nanjing University of Science and Technology Nanjing 210094 China2. College of Materials Science and Engineering Southeast University Nanjing 211189 China

Ultra-high performance cementitious composites (UHPCC) were prepared by replacing 60% of cement with ultra-fine industrial waste *** dynamic damage and compressive stress-strain relations of UHPCC were studied using split Hopkinson pressure bar (SHPB).The damage of UHPCC subjected to repeated impact was measured by the ultrasonic pulse velocity *** show that the dynamic damage of UHPCC increases linearly with impact times and the abilities of repeated impact resistance of UHPCC are improved with increasing fiber volume *** stress waves on impact were recorded and the average stress,strain and strain rate of UHPCC were calculated based on the wave propagation *** effects of strain rate,fibers volume fraction and impact times on the stress-strain relations of UHPCC were *** show that the peak stress and elastic modulus decrease while the strain rate and peak strain increase gradually with increasing impact times.

关键词： ultra-high performance cementitious composites (UHPCC) split Hopkinson pressure bar (SHPB) repeated impact damage stress-strain

Constructing Three-Dimension Space Graph for Outlier Detection Algorithms in Data Mining

在线全文

学校读者我要写书评

暂无评论

Wuhan university Journal of Natural sciences 2004年第5期9卷 585-589页

作者： ZHANG Jing 1,2 , SUN Zhi-hui 1 1.department of computer science and Engineering, Southeast university, nanjing 210096, jiangsu, china 2.department of Electricity and Information Engineering, jiangsu university, Zhenjiang 212001, jiangsu, china department of computer science and Engineering Southeast University. Nanjing 210096 Jiangsu China

Outlier detection has very important applied value in data mining literature. Different outlier detection algorithms based on distinct theories have different definitions and mining processes. The three-dimensional space graph for constructing applied algorithms and an improved GridOf algorithm were proposed in terms of analyzing the existing outlier detection algorithms from criterion and theory. Key words outlier - detection - three-dimensional space graph - data mining CLC number TP 311. 13 - TP 391 Foundation item: Supported by the National Natural science Foundation of china (70371015)Biography: ZHANG Jing (1975-), female, Ph. D, lecturer, research direction: data mining and knowledge discovery.

关键词： outlier detection three-dimensional space graph data mining